qqint LED1 = 1;
int LED2 = 2;
int LED3 = 3;
int pb1 = 4;
int pb2 = 5;
int pb3 = 6;
int pb4 = 7;

int pbstate1 = 0;
int pbstate2 = 0;
int pbstate3 = 0;
int pbstate4 = 0;

void setup() {
  pinMode (LED1, OUTPUT);
  pinMode (LED2, OUTPUT);
  pinMode (LED3, OUTPUT);
  pinMode (pb1, INPUT);
  pinMode (pb2, INPUT);
  pinMode (pb3, INPUT);
  pinMode (pb4, INPUT);
}

void loop() {
  pbstate1=digitalRead(pb1);
  if(pbstate1 == HIGH) {
    digitalWrite(LED1, HIGH);
    digitalWrite(LED2, LOW);
    digitalWrite(LED3, LOW);
    delay(100);
  }
  else {
digitalWrite(LED1, LOW);
digitalWrite(LED2, LOW);
digitalWrite(LED3, LOW);
  }

  pbstate2=digitalRead(pb2);
  if(pbstate2 == HIGH) {
    digitalWrite(LED1, LOW);
    digitalWrite(LED2, HIGH);
    digitalWrite(LED3, LOW);
  }
  else {
    digitalWrite(LED1, LOW);
    digitalWrite(LED2, LOW);
    digitalWrite(LED3, LOW);
  }
  pbstate3=digitalRead(pb3);
  if(pbstate3 == HIGH) {
    digitalWrite(LED1, LOW);
    digitalWrite(LED2, LOW);
    digitalWrite(LED3, HIGH);
  }
  else {
    digitalWrite(LED1, LOW);
    digitalWrite(LED2, LOW);
    digitalWrite(LED3, LOW);
  }

  pbstate4=digitalRead(pb4);
  if(pbstate4 == HIGH) {
    digitalWrite(LED1, HIGH);
    digitalWrite(LED2, HIGH);
    digitalWrite(LED3, HIGH);
  }
  else {
    digitalWrite(LED1, LOW);
    digitalWrite(LED2, LOW);
    digitalWrite(LED3, LOW);
  }
}